Blindfold Computer Opponents

The hardest task when creating a game is to come up with an algorithm for a computer opponent.  Unless I am designing a game where you play against other humans, the only way a game will be considered enjoyable is if the computer opponent is smart.  Finding an algorithm to make the computer appear smart can be quite challenging.  Despite what you think if you’ve ever played one of the games, Blindfold Games computer opponents never cheat.

picture of robot head

For card games like Blindfold Hearts, Blindfold Spades and Blindfold Rummy, I found computer science research papers that outlined the optimal strategy for a player.  For example, the method used in Blindfold Rummy is even more complex than the game rules themselves.  First the computer determines the number of complete groups (like 3 of a kind), and the number of complete runs (like Jack, Queen, King of Spades), then it determines the number of partial groups and runs, and computes the resultant deadwood for each hand combination (in Rummy, you try to minimize your deadwood).  It keeps track of cards that are discarded, so it knows what may still be in the deck, or in the human player’s hand.  Based on that information, it makes a pretty good decision about what to do.

The computer also determines the worst possible move – one that will generate the most amount of deadwood, and finally, it generates a random move.  When it’s the computer’s turn, it will pick either the best move, the worst move or the random move.

To prevent the computer from always winning, I created 4 categories of players and assigned each a skill level, a Poor Player is rated as 10, Average is 20, Good is 30 and Very Good is 40.  Then I generate a luck number to indicate how lucky the player’s next move is.  For each move, the luck number is randomly picked, and is between 1 and 40.

For each move, I add those two numbers together. Hence the Poor Player’s combined luck plus skill number can be between 11 and 50, and the Very Good Player’s combined number will be between 41 and 80.  If the combined number is greater than 45, the best move is picked.  If the combined skill plus luck number is less than 30, the worst move is picked.  If the combined number is between 30 and 45, the random move is picked.

Roughly speaking, the Poor Player will make a bad move about 90% of the time, and a good Player will make the optimal move about 90% of the time.

The next new feature I may add to the games is a ghost player.  A ghost player has the same win-loss ratio that you do, so, in essence, you are playing against yourself.  I’ll probably do that in Blindfold Bowling first, and then move it to some of the other games.




Blindfold Games: Upcoming Conferences

In addition to creating games, I continue to test different ways to spread the news about the Blindfold Games.  Word of mouth is effective, and I participate in podcasts or interviews whenever there’s an opportunity, but I know I’m still on reaching a minority of visually impaired iPhone and iPad owners.

person with megaphone talking to crowd

There are several conferences going on this summer, so I’m trying something different in each of them.  At the ACB conference, I’m running an advertisement in the show newsletter every day, with a different offer each day.  At the NFB conference in Orlando – a reasonable short drive from my home – I have a table in the exhibitor’s room, and will have game info in both large print and braille, and I’ll be demonstrating the games.  In another show in the Massachusetts area, I put a brochure offering a free game everyone’s show bag.

Based on the results, there are other conferences, both in the US and in Europe, that may be worth attending.  The main consideration is the return-on-investment; between the cost of brochures, airfare, hotel and exhibitor fees, or the cost of advertising,  it’s critical that the conference generates enough new game downloads and in-app upgrades to break even.

I’ve run a handful of contests and give-aways with a few websites that provide services or products to the blindness community, but none had a significant impact.

One of my long term goals with Blindfold Games is to create a viable marketing and distribution channel to reach the visually impaired community.  Once this channel is well established, many other developers of games or related technologies will be less reluctant to address this market.  Right now, most developers shy away from this market because it is so hard to reach the consumer, and over the past decade, many developers have dropped out because of the marketing difficulties.

If you have ideas on how to spread the word, please write to me.  And if you’re going to the NFB show, stop by table “A” 19 and say hello.









Blindfold Basketball: Drawing on the screen

In my prior post, I talked about how you could draw on the screen to select a type of basketball shot, such as a dunk shot, or a hook shot or a jump shot.  I thought this would be more interesting than simply flipping through a menu of shots, and while some testers wanted the menu, most wanted to draw the gesture.

pen drawing a checkmark

As usual, I learned that I was making some false assumptions about drawing on the screen.  In my initial version, a hook shot looked like the letter V, and a jump shot looked like the letter J.  In both gestures, you swipe your finger down to the right, and then up again to the right.  The difference is that both the downstroke and the upstroke in the letter V are almost identical in length, while in the letter J, the downstroke is short and the upstroke is long.

Many of the testers told me the game didn’t detect their hook shot or jump shot correctly.  The app assumed that if the downstroke with less than 1/3 of the length of the upstroke, it was the letter J instead of the letter V.  When I finally discovered what was going on, I realized that without looking at the screen, it’s hard to measure the length of your strokes.  Some of the testers had no problem, but enough did that I had to change it.

In the next version, I changed the gestures to always use the letter V shape for both jump and hook, but you start from the left for a hook shot, drawing the down and up strokes to the right, and you start from the right for a jump shot, drawing the down and up strokes to the left.

I did similar changes for the dunk shot, free throw and post shots.  Everyone said the game was much easier to use.





Blindfold Pool: Is it even possible?

When I start getting lots of requests for a game, it piques my interest to see if it can be created as an audio game.  Since many games were previously created as a text game on a Windows PC, if someone suggests football or pool, they are often just asking for that same type of game on the iPhone.  A baseball game may let you pick a player, a type of pitch and a type of swing, and then the game tells you what happened.  That might be fine for a simple windows text game, in an iPhone game, a rich audio environment and relevant gestures are what makes the games fun.

rack of pool balls


I thought pool, also known as billiards, couldn’t even be done as an audio game.  In the real game of pool, you must hit the cue ball at the colored ball at just the right angle so it lands in the designated pocket.  And you have to hit the cue ball at just the right spot, so it sets up the next correctly, using a forward, side or backward spin.  When I played some iPhone video pool apps, lining up a shot took about 3 different actions, and I had to consider many different angles on the screen at once.  Giving that much audio information would make the audio game overly complex.

I started by first doing the rack break – the first shot in a pool game.  To break the rack in Blindfold Pool –  in other words, hit the cue ball at the triangle formation the balls at the other end of the pool table, you just swipe your finger.  The more powerful your swipe, the faster the cue ball goes.  You hear the sounds of the balls rolling in all directions on the pool table, and some may sink into a pocket.

For aiming & shooting though, I simplified the game by eliminating the cue ball.  You just line up your shot so the colored ball would go into the selected pocket.  When playing, you hear a ding meaning your shot is lined up, and then you swipe.

All this was great, until I sent out the first version for testing.  That’s when the confusion began.  More in another blog.




Blindfold Games: Basketball Attempt #5

In my last blog, I talked about how the wrist-snapping gestures for dribbling and shooting the basketball went over like a lead balloon.

grid layout of basketball court

Based on everyone’s suggestions, I switched from phone actions to screen gestures.  In the  normal setup, you pick your shot by first double tapping the screen, then scrolling through a menu of shots: hook shot, jump shot, post shot, free throw and dunk shot.  The shots only work when appropriate; you can’t do a dunk shot unless you are directly at the basket, and you wouldn’t do a free throw when you are at the basket.

For those users that like drawing the shot gesture on the screen, I created an option to do that.  A post shot in real life involves turning around in a circle as you jump up and slam the ball into the basket.  To select a post shot, you can also draw a circle on the screen.  For a hook shot, you draw an upside-down vee shape, similar to the action of a hook.

To dribble the ball, you just tap the screen, and you hear the ball bounce.  I created an option to let you snap your wrist when holding the phone, as if you were bouncing the ball.

Everyone liked the new gestures, but now people thought the court layout was too artificial.  I created the court as a 9 row by 9 column grid, labeling each row from the letters A to I, and the columns as the numbers 1 to 9.  The basket is at A 5.  As you move around the court, the game stated your position, such as D 3.

One of the testers said she didn’t get the feel of the basketball court, so I changed the entire game to give directional location and distance from the basket.  For example, when you start, the game says you are 40 feet from the basket, and the basket is at 12 o’clock.  When you move forward and the to left, the game says you are 20 feet from the basket, and the basket is at 2 o’clock.

Almost everyone liked the new positioning, so I’m now working on the coach games.  In the coach games, a coach tells you where on the court to go, and what shot to make.  The next phase is to add other players to the game, and give you a way to determine where those players are.  This will be a great way to build up your basketball skills so you can play a complete game.






Blindfold Games: Running in circles

I’ve been working on Blindfold Basketball for the past three weeks, and feel like I’m running in circles.

finger swiping

In the first test version of the game, I created 5 different screen gestures for each type of shot one could make in basketball, including dribbling, hook shots, post shots, 3 point shots and free throws.

For example, to make a hook shot, you draw a vee on the screen with your finger: first you swipe down to the right, then swipe up to the right, aiming for the basket.

In the first beta version, most of the testers were underwhelmed or confused.    Several said the phone should be used as part of the shot, as if the phone were the ball, and you could dribble or shoot by moving the phone.

The second test version of basketball explored that idea.  After about a week of experimentation with the gyroscope and accelerometer in the phone, I came up with several cool ways to use the phone.  With the phone screen facing the ceiling so the phone is horizontal, you bounce  the ball by snapping your wrist down, just like you would bounce a ball.   To aim, you move your arm left or right so it’s aimed in the direction of the basket.  To shoot, you tilt your wrist up so the phone is vertical, and snap your wrist down, as if you are throwing a ball away from you.

Unfortunately, the phone’s gyro was too unpredictable to make this work reliably, after another week of experimentation, I changed shooting in that you still snap your wrist, but you must keep a finger pressed on the screen.  In other words, to dribble, snap your wrist without a finger on the screen, to shoot, snap your wrist with a finger on the screen.

The majority of the testers said that was nice, but they preferred screen gestures.  We’re now testing a variety of gestures to pick your shot, and I wouldn’t be surprised if I end up back where I started.  I guess I can use the 3 weeks of development to perfect the wrist snapping gesture to build a fishing game.



Blindfold Games June Update

I often get asked for a list of games that we’ve built.  Here’s the current list, from the newest to the oldest.

Click on the game to go directly to the iTunes download page.  All games are designed for rapid audio play and have been built with the help of dozens of visually impaired gamers.

Blindfold Checkers – Play checkers with easy, medium or expert opponents.

Phrase Madness – Famous as a windows game, now on the iPhone and iPad.  Match the phrases and laugh your socks off.

Blindfold Pinball – Play pinball on diffferent pinball machines.

Blindfold Pool – Play pool by hitting your cue ball into the other balls, and landing them in the pockets.  Hours and hours of fun.

Blindfold Spin and Solve – Inspired by Wheel of Fortune, spin to guess a letter in the phrase and win.

Blindfold Shuffleboard  – Slide your discs into the scoring area, and push your opponents discs out of the way.

Blindfold Road Trip– Be the first player to drive 1000 miles in this card game similar to 1000 miles or Miles Bornes.

Blindfold Bingo – Play bingo with lots of patterns. Win coins. Record yourself saying Bingo and share it.

Blindfold Crazy Eights with Friends – Crazy Eights card game with with other people, via Game Center or in the same room.

Blindfold Barnyard– Move your animals from the barnyard to the fence to the barn. It’s addicting!

Blindfold Word Games– Hangman, Word Ladder, Scramble and Word Flick.

Blindfold Horse Race– Race against other horses by walking your fingers on the screen.

Blindfold Juggle– Juggle animals on earth and other planets.

Blindfold Color Crush – A cross between Bejeweled and Candy Crush.

Blindfold Rummy – Gin Rummy card game – collect sets and runs of cards.

Blindfold Tile Puzzle – Tile games including 2048 and Threes, with several variations.

Blindfold Vee Ball – Just like Skee ball: Roll a ball up a ramp to land in the highest point hole.

Blindfold Craps – Dice game where you bet on the outcome of a dice roll, just like in Las Vegas.

Blindfold Air Hockey – Air Hockey – use your mallet to shoot the puck into your opponent’s goal.

Blindfold Breakout – Breakout game where you smash bricks with a ball, similar to the arcade game.

Blindfold Bowling – Ten pin bowling just like at the bowling alley.

Blindfold Roulette – Play roulette just like in Las Vegas.

Blindfold Hopper – Inspired by the old video game frogger.

Blindfold Pong – Pong game similar to the classic arcade game.

Blindfold Dominoes -Dominoes game where you play until you are out of tiles or blocked.

Blindfold Hearts – Hearts card game where you avoid collecting hearts or you can shoot the moon.

Blindfold Simon – My Simon type game where you follow patterns based on gestures and sounds.

Blindfold Spades – Spades card game where you bid and collect tricks as you win each hand.

Blindfold War – The classic war card game where you try to collect all the cards.

Blindfold Solitaire – Solitaire card games including Klondike, Spider, Free Cell, Golf and many others.

Blindfold Wildcard – An Uno type card game.

Blindfold Crazy Eights – Crazy Eights card game with several variants of play.

Blindfold Video Poker – Video Poker just like the machines in Las Vegas.

Blindfold Blackjack – Play Blackjack against the dealer.

Blindfold Sudoku – Audio Sudoku in a 9 by 9 grid, with easy, medium and hard levels.

Blindfold Sudoku Mini – Audio Sudoku in a 4 by 4 grid, lots of fun and great for people who never played Sudoku before.

Blindfold Cryptogram – Decode famous quotes and phrases in a letter substitution game

Blindfold Racer – Drive your car using your ears, not your eyes.  The original game that started all of this.